This invention relates to a system for generating electrical power from the motion of the sea, particularly utilizing undersea waves.
There have been published many articles and patents on methods and system for producing electrical power from the ocean waves. However, these have been concerned with using ocean surface waves. The equipment or floats for the equipment ride on the surface. Typical of these approaches are the systems described by Arlyn H. Jackson in U.S. Pat. No. 4,091,618 and Lawrence C. Burton in U.S. Pat. No. 4,931,662. Jackson's system utilizes a floating buoy attached to a pump which pumps water from a submerged tank below the float. The motion of the surface waves moves the buoy up and down, operating the pump to create a void in the submerged tank, thus creating a hydrostatic head. This hydrostatic head is used to drive a turbine and generate electric power.
The Burton patent describes a large circular float on the water surface which is attached to one end of a long, rigid beam. The Burton patent describes a large circular float on the water surface which is attached to one end of a long, rigid beam. The other end of the beam is supported and pivoted on a platform. The motion of the float, up and down, is transmitted to the platform where it can be used to pump hydraulic fluids and drive an electric generator.
Some of the more recent schemes have been described in the Los Angeles Times on Jun. 28, 1991. One is a system by Robert A. Bueker, who calls his system a Seamill. This is a device consisting of three 33 foot long pipes, one inside the other, that hold a small turbine driven by the ocean swells.
Another system by Stuart Pringle, illustrates a pier run out into the ocean. Suspended beneath the pier are vertical pistons which are connected to floats riding on the water surface. The pistons are moved up and down by the wave swells and compress air other fluid to drive turbine generators.
The incentive to produce the systems such as described above depends on the increasing public demand to use `clean` non-polluting power generation, as well as a projected lower cost per kilowatt-hour. For example, according to Bueker, his Seamill can generate electricity at 1.5 to 3 cents a kilowatt-hour if sufficient surface wave energy is present. This compares with a Southern California Edison Co. cost averaging 3.6 cents a kilowatt-hour in 1990. There are, however, considerable political obstacles in the way of citing any significant shore-based system, such as described above, along the highly regulated shorelines of states, such as California. An off-shore system, using wave power, would reduce the political objections considerably.
Studies published in the Journal of Geophysical Research and other journals on oceanography, have revealed the existence of undersea internal waves occurring at various depths off the California coats. These waves have considerable and far more constant energy that surface waves, and could be harnessed to generate electrical power. It therefore would be new and useful to provide an off-shore system for generating electric power from undersea waves.